title: [Clinical diagnostic value of (18)F-FDG PET-CT in incidental finding of focal hypermetabolism focus in the colon and rectum].
abstract: OBJECTIVE
  To investigate the value of incidental focal (18)F-FDG uptake in the colon and rectum and characteristics of functional anatomic form for differential diagnosis of colorectal benign or malignant diseases.
  
  
  METHODS
  Clinical data and images of incidental focal hypermetabolism focus in colon and rectum of 37 individuals undergoing (18)F-FDG PET-CT were analyzed retrospectively. According to the eventual outcomes of pathological examination and clinical follow-up, these cases were divided into four subgroups: malignant disease, benign tumor (including precancerous change), inflammation and physiological uptake. Radioactive uptake level (SUVmax) and change of delayed imaging (RI) of focal hypermetabolism focus were compared between groups. The data analysis was performed using variance analysis.
  
  
  RESULTS
  The average SUVmax was 6.3±3.7, 8.8±6.5, 5.2±1.4, and 3.8±0.9 in malignant disease (n=11), benign (precancerous) tumor (n=9), inflammation (n=9) and physiological uptaking (n=8) respectively. The average SUVmax was 7.6±5.6 in benign and malignant tumor, and 4.7±1.5 in inflammation and physiological uptake. The distinction of average SUVmax was not statistically significant between benign and malignant tumor or inflammation and physiological uptake. But it was higher in tumors as compared to inflammation or physiological uptake with a statistically difference (P<0.05). The RI was 0.3±0.2, 0.4±0.1, 0.3±0.2, 0.4±0.2 in above 4 groups respectively, and the differences were not statistically significant.
  
  
  CONCLUSIONS
  The incidental focal hypermetabolism focus in the colon the rectum during (18)F-FDG PET-CT may indicate potential colorectal malignant diseases and precancerous lesions. SUVmax value in focal hypermetabolism focus in the colon and rectum can help to distinguish tumor from inflammation or physiological uptake. But there is no diagnostic value for distinguishing malignant disease from benign tumor.
authors.affiliation: PET-CT Center, 113 Hospital of PLA, Zhejiang Ningbo 315040, China. sundaect@hotmail.com.
authors.forename: Guo-zheng
authors.initials: GZ
authors.lastname: Wu
authors.forename: Da
authors.initials: D
authors.lastname: Sun
authors.forename: Jian-yong
authors.initials: JY
authors.lastname: Chen
authors.forename: Ji-miao
authors.initials: JM
authors.lastname: Qiu
authors.forename: Yan
authors.initials: Y
authors.lastname: Kong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003108:Colonic Diseases / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D012002:Rectal Diseases / Q000000981:diagnostic imaging*; D012189:Retrospective Studies
chemical_list: D019788:Fluorodeoxyglucose F18